1. Technical Field
The disclosure relates to a capacitive transducer and a fabrication method thereof.
2. Technical Art
In the hearing instrument and mobile communication system industry, the trend is to make components of small sizes while still maintaining good electro-acoustic performance and operability, thereby ensuring good user friendliness and satisfaction. In the past, several attempts have been made to make microphone systems smaller while maintaining or improving their technical performance data.
US 2008/0157238 discloses a MEMS (micro-electro-mechanical systems) microphone module having an application specific IC and a microphone chip. The application specific IC has a plurality of first vias and a plurality of first pads, and the first vias are connected to the first pads. The microphone chip has a resonant cavity, a plurality of second vias and a plurality of second pads, and the second vias are connected to the second pads.
U.S. Pat. No. 7,166,910 discloses a silicon condenser microphone package comprising a transducer unit, a substrate, and a cover. The substrate includes an upper surface having a recess formed therein. The transducer unit is attached to the upper surface of the substrate and overlaps at least a portion of the recess, wherein a back volume of the transducer unit is formed between the transducer unit and the substrate.
U.S. Pat. No. 6,781,231 discloses a microelectromechanical system package with a microelectromechanical system microphone, a substrate, and a cover. The substrate has a surface for supporting the microelectromechanical microphone. The cover includes a conductive layer having a center portion bounded by a peripheral edge portion. A housing is formed by connecting the peripheral edge portion of the cover to the substrate. The center portion of the cover is spaced from the surface of the substrate to accommodate the microelectromechanical system microphone. The housing includes an acoustic port for allowing an acoustic signal to reach the microelectromechanical system microphone.
U.S. Pat. No. 6,732,588 discloses a compact solid state silicon-based condenser microphone system suitable for batch production. The microphone system includes a transducer chip comprising a chamber, a diaphragm positioned at the first lower surface and covering the second opening of the transducer chip. The transducer chip is flip-chip mounted onto a post-processed chip also comprising a chamber.